Alaska Extended Forecast Discussion
NWS Weather Prediction Center College Park MD
630 PM EST Sun Nov 28 2021
Valid 12Z Thu Dec 02 2021 - 12Z Mon Dec 06 2021
...Well below normal temperatures over southwestern Alaska will
likely be followed by snowy and windy conditions late this week
and into early next week...
...Guidance Evaluation/Preferences...
Similar to yesterday, the new guidance today appears to show
enough compatibility with each other that a general model
compromise should offer a good starting point through Day 8. A
40% blend of the 12Z GFS/GEFS with 40% 12Z ECMWF/00Z EC mean, and
20% from the 12Z CMC/CMC mean was adopted from Days 4 to 6.
Higher percentages from the ensemble means were then used for Days
7 and 8. This blend yielded a solution very similar to
yesterday's forecasts with slight acceleration of the next frontal
system of concern across the Bering Sea next Friday.
...Weather/Hazard Highlights...
An occluded cyclone hovering near the southern coast of Alaska
midweek will likely weaken further through the end of the week,
leading to a decreasing chance of precipitation through the
southern periphery of Alaska and down along the Panhandle.
Radiational cooling will likely keep temperatures much below
normal for much of the southwestern mainland for the latter part
of the week before a series of energetic frontal systems brings
milder air from the south as well as periods of snowy and windy
weather into western Alaska by Friday and into early next week.
Occasional rain and windy conditions can be expected farther south
along the Aleutians into the Alaska Peninsula by next weekend.
Kong
Additional 3-7 Day Hazard Information can be found on the WPC
medium range hazards outlook chart at:
https://www.wpc.ncep.noaa.gov/threats/threats.php
WPC medium range Alaskan products including 500mb, surface
fronts/pressures progs and sensible weather grids can also be
found at:
https://www.wpc.ncep.noaa.gov/alaska/ak_5dayfcst500_wbg.gif
https://www.wpc.ncep.noaa.gov/alaska/akmedr.shtml
https://www.wpc.ncep.noaa.gov/alaska/ak_5km_gridsbody.html